JPH03222689A - Brushless motor driver - Google Patents

Abstract

PURPOSE:To start a motor smoothly by outputting a conduction switching pulse preferentially if it is produced while outputting a conduction state transition pulse if the conduction switching pulse is not inputted within a predetermined time. CONSTITUTION:When a rotor is rotated through conduction switching with a starting pulse Po and a voltage is induced, conduction switching pulses PU, PV, PW are outputted. If the conduction switching pulses PU, PV, PW are produced earlier than a time predetermined by a timer circuit 4, the timer circuit 4 is reset before the predetermined time elapses and thereby no starting pulse Po is produced, and conduction switching of driving coils 8a-8c is carried out by means of the conduction switching pulses PU, PV, PW. More specifically, if the conduction phases of the driving coils 8a-8c are not switched even upon elapse of the predetermined time, the conduction state is switched and the conduction phase is switched preferentially with the timing of the conduction switching pulses PU, PV, PW.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a drive device for a brushless motor used in audio equipment, video equipment, and the like.

Conventional technology In recent years, motors used in audio equipment, video equipment, etc. have been using conventional brushes for their high reliability and long life.

Instead of a DC motor having a commutator, the rotational position of the rotor is detected by a position detector, and a plurality of drive transistors connected in series with multi-phase coils are sequentially turned on to connect the rotation of the rotor. So-called brushless motors configured in this manner are increasingly being used.

Hereinafter, a conventional brushless motor drive device will be described with reference to the drawings.

FIG. 4 is a circuit connection diagram of a conventional brushless motor drive device, 101a, 101b, 101. C is a drive coil, which is reset by the time 103a, 103b, and 10'3c are received, so that the starting pulse P is generated.

does not occur, and the energization of the drive coil is switched by the energization switching bars JLs Pu, Pv, and Pw. As described above (when the induced voltage is not detected, the energizing phase of the drive coil is switched by the starting pulse, and when the induced voltage is generated and the energizing switching pulse is input to the energizing state transition command circuit 5, the energizing switching pulse is generated at that moment. The energization of the drive coil is switched in synchronization with the .Thus, it is possible to realize smooth starting of the motor.

Furthermore, although the embodiment of the present invention has been described using a three-phase half-wave drive method as an example, other drive methods such as a two-phase half-wave drive method and a four-phase full-wave drive method can also be realized. .

Effects of the Invention As is clear from the above explanation, the present invention provides an energized state if the energized phase of the drive coil is not switched even after a predetermined time has elapsed when the induced voltage of the drive coil 1 of the motor cannot be detected. The transition pulse switches the energization state and generates an induced voltage, and when the energization switching pulse is output, the energization phase is switched preferentially at the timing of the energization switching pulse, allowing smooth motor startup. . Furthermore, the present invention can be applied to a two-phase half-wave drive system, a three-phase full-wave drive system, etc., and can be realized regardless of the drive system.

[Brief explanation of drawings]

Fig. 1 is a circuit connection diagram of a brushless motor drive device according to an embodiment of the present invention, Fig. 2 is an operation signal waveform diagram when the motor in Fig. 1 is rotating steadily, and Fig. 3 is a diagram when the motor is started in Fig. 1. FIG. 4 is a circuit connection diagram of a conventional brushless motor drive device, and FIG. 5 is an operating signal waveform diagram in FIG. 4. ■・・・-・・・Electrification switching pulse generation circuit, 2...
... Energization switching circuit, 3... Energization phase transition pulse output circuit, 4... Timer circuit, 5...
Energization state transition command circuit, 6... Energization switching signal amplification circuit, 7a, 7b, 7c... Drive transistor, 8a, 8b, 8c... Drive coil. Figure W (IJTW Figure UTW W

Claims (1)

[Claims] A multi-phase motor drive coil, a plurality of drive transistors connected to the drive coil, an energization switching circuit that sequentially transmits an energization switching signal of the drive coil to the drive transistor, and a energization switching circuit that detects an induced voltage of the drive coil. an energization switching pulse generation circuit that outputs energization switching pulses for the number of phases;
An energization state transition command circuit inserted between the energization switching pulse generation circuit and the energization switching circuit detects switching of the energization switching signal and generates an energization phase transition pulse every time the energization phase of the drive coil is switched. and a timer circuit that outputs a starting pulse when a predetermined time elapses after the energization phase transition pulse is input, and the energization state transition command circuit outputs the energization switching pulse. A brushless motor driving device configured to output an energization switching pulse preferentially when the energization switching pulse occurs, and to output an energization state transition pulse when the energization switching pulse is not input within the predetermined time.